Preoperative Concurrent Chemoradiotherapy for Locally Advanced Rectal Cancer: Treatment Outcomes and Analysis of Prognostic Factors

PURPOSE This study was designed to investigate the long-term oncologic outcomes for locally advanced rectal cancer patients after treatment with preoperative concurrent chemoradiotherapy followed by total mesorectal excision, and to identify prognostic factors that affect survival and pathologic response. MATERIALS AND METHODS From June 1996 to June 2009, 135 patients with locally advanced rectal cancer were treated with preoperative concurrent chemoradiotherapy followed by total mesorectal excision at Kyung Hee University Hospital. Patient data was retrospectively collected and analyzed in order to determine the treatment outcomes and identify prognostic factors for survival. RESULTS The median follow-up time was 50 months (range, 4.5 to 157.8 months). After preoperative chemoradiotherapy, sphincter preservation surgery was accomplished in 67.4% of whole patients. A complete pathologic response was achieved in 16% of patients. The estimated 5- and 8-year overall survival, loco-regional recurrence-free survival, and distant metastasis-free survival rate for all patients was 82.7% and 75.7%, 76.8% and 71.9%, 67.9% and 63.3%, respectively. The estimated 5- and 8-year overall survival, loco-regional recurrence-free survival, and distant metastasis-free survival rate for pathologic complete responders was 100% and 100%, 100% and 88.9%, 95.5% and 95.5%, respectively. In the multivariate analysis, pathologic complete response was significantly associated with overall survival. The predictive factor for pathologic complete response was pretreatment clinical stage. CONCLUSION Preoperative chemoradiotherapy for locally advanced rectal cancer resulted in a high rate of overall survival, sphincter preservation, down-staging, and pathologic complete response. The patients achieving pathologic complete response had very favorable outcomes. Pathologic complete response was a significant prognostic factor for overall survival and the significant predictive factor for a pathologic complete response was pretreatment clinical stage.